Medizinische Universität Graz - Research portal
Selected Publication:
Schobel, L.
A technical concept for using the cold pressor test during MRI.
[ Diplomarbeit/Master Thesis (UNI) ] TU Graz; 2023. pp.84.
FullText
- Authors Med Uni Graz:
- Advisor:
- Ropele Stefan
- Altmetrics:
- Abstract:
- Cerebrovascular compliance (CVC) mapping with magnetic resonance imaging (MRI) is based on measuring vasoconstriction with quantitative susceptibility mapping (QSM) as a consequence of a change in arterial blood pressure. CVC has many clinical applications, but its potential largely depends on the capabilities to non-invasively inducing a stressor for the arterial blood pressure. To achieve a change in arterial blood pressure (BP), the use of cold pressor test (CPT) has been investigated in previous studies. However, the correlation between the parameters and the greatest possible effect has never been collected. In this study, the correlation between temperature, application time and application area was investigated in relation to the BP change. The results showed, that all stimuli led to a significant and clearly visible change of the arterial BP. Further a trend could be detected, that a larger application area and a longer application time leads to a greater increase in BP, but it was not possible to verify the observations with statistically significance. The temperature for the test must be between 0 °C and 4 °C to obtain a significant BP change without posing a risk to the subject or patient. To enable application in a magnetic resonance (MR) scanner, a method for cold application without direct fluid contact was sought and a device was designed. The application part is made of aluminium nitride (ALN) ceramics and was adapted to the sole of the foot. Cold liquid flows through the cooling device. In order to be able to switch from hot to cold within a few seconds, two fluid circuits were implemented. Before starting the test, warm liquid is pumped through the application part to bring the foot to body temperature. By starting the test, the coolant is pumped through the application part. After the set time has elapsed, the warm circuit is reactivated to allow rewarming. The development of this device was carried out in compliance with the medical device regulation (MDR) and applicable standards to allow approval as a medical electrical device.